biology exam 1

Life's Hierarchy

Levels from atom to biosphere, each representing different aspects like populations and communities.

Basic Characteristics of Life

Includes characteristics like order, which refers to the hierarchy and structure of living things.

Order

Life's hierarchy and structure of living things, exemplified by symmetry in humans or seed arrangement in sunflowers.

Metabolism

The chemical processes that occur within a living organism to maintain life.

Homeostasis

The ability of an organism to maintain internal stability and adjust to environmental changes.

Behavior

The actions or reactions of an organism in response to stimuli or its environment.

Evolution vs. Natural Selection

Evolution is the gradual change in a species over time, while natural selection is the mechanism by which advantageous traits are passed on.

Father of Taxonomy

Linnaeus

Taxonomic Levels

Domain -> Kingdom -> Phylum -> Class -> Order -> Family -> Genus -> Species

Scientific Method

A systematic approach to research with steps including observation, hypothesis, experimentation, and conclusion.

Variables

Independent variable is manipulated, dependent variable is measured, and extraneous variables are controlled.

Control

A standard for comparison in an experiment, unaffected by the independent variable.

Constant

A factor that remains unchanged throughout an experiment.

Scientific Theory

A well-substantiated explanation of some aspect of the natural world based on a body of facts.

Scientific Law

A statement based on repeated experimental observations that describes an aspect of the natural world.

Atom

The basic unit of matter, composed of protons, neutrons, and electrons.

Electron Shells

Energy levels where electrons orbit around the nucleus of an atom, with a specific capacity for electrons.

Valence Shell

The outermost electron shell of an atom, important for chemical bonding.

Electronegativity

The tendency of an atom to attract a shared pair of electrons in a covalent bond.

Ionic Bond

A chemical bond formed by the transfer of electrons between atoms.

Polar Covalent Bond

A covalent bond where electrons are shared unequally between atoms.

Non-Polar Covalent Bond

A covalent bond where electrons are shared equally between atoms.

Dipole Moment

A measure of the separation of positive and negative electrical charges in a molecule.

Hydrogen Bond

A weak bond between a hydrogen atom and an electronegative atom.

Emergent Properties of Water

Include cohesion and adhesion, crucial for processes like water transport in plants.

Calorie vs. Calorie

A calorie is a unit of energy, while a Calorie (kilocalorie) is used to measure the energy content of food.

Evaporative Cooling

The process where heat is absorbed during evaporation, leading to a cooling effect.

Solution

A homogeneous mixture composed of a solute dissolved in a solvent.

Solvent

The substance in which the solute dissolves to form a solution.

Solute

The substance that is dissolved in a solution.

Hydration Shell

The sphere of water molecules around dissolved ions.

Hydrophilic

Having an affinity for water, tending to dissolve in water.

Hydrophobic

Repelling water, not tending to dissolve in water.

Organic vs. Inorganic Chemistry

Organic chemistry deals with compounds containing carbon, while inorganic chemistry deals with compounds lacking carbon.

Carbon's Special Properties

Carbon can form four covalent bonds, leading to diverse molecular structures.

Carbon's Valence Electrons

Carbon has four valence electrons.

Carbon's Tetrahedron Shape

If carbon forms a tetrahedron, the angle between the bonds is 109.5 degrees for optimal spatial arrangement.

CO2 Structure

Carbon dioxide is composed of one carbon atom double-bonded to two oxygen atoms.

Hydrocarbons

Compounds made of hydrogen and carbon atoms, important in biological and industrial contexts.

Carbon Skeletons

Carbon can form chains, branched structures, or rings in molecules.

Isomers

Molecules with the same molecular formula but different structures.

Functional Groups

Specific groups of atoms within molecules that confer specific chemical properties.

Dissociation of Water

The splitting of water molecules into H+ and OH- ions.

pH Scale

A logarithmic scale measuring the acidity or basicity of a solution.

Buffer

A substance that resists changes in pH by accepting or releasing hydrogen ions.

Carbonic Acid as Buffer

Carbonic acid helps maintain blood pH by acting as a buffer.

Ocean Acidification

The process by which the ocean becomes more acidic due to increased carbon dioxide levels.